Answer is:
proportional limit, elastic limit, yielding, failure
Explanation:
1) proportional limit
2) elastic limit
3) yielding
4) failure

Answer is:
elastic limit
Explanation:
Hook's law holds good up to elastic limit.

Answer is:
directly proportional to
Explanation:
Whenever a material is loaded within elastic limit, stress is directly proportional to strain

Answer is:
modulus of elasticity
Explanation:
The ratio of linear stress to the linear strain is called as modulus of elasticity (Young's Modulus)

Answer is:
stress, pressure and modulus of rigidity
Explanation:
The unit of modulus of elasticity is same as those of stress, pressure and modulus of rigidity.
